Dissolve yeast in water; let stand 5 minutes or until bubbly. Set aside.
Combine flour, 1 tablespoon sugar, and salt in a large mixing bowl; mix well. Cut in shortening with a pastry blender until mixture resembles coarse meal. Combine eggs and milk; gradually add to flour mixture, beating at medium speed of electric mixer until smooth. Add yeast mixture, mixing well. Place in a greased bowl, turning to grease top. Cover and let rise in a warm place (85°), free from drafts, 2 hours or until doubled in bulk.
Punch dough down. Sprinkle lightly floured surface with sugar. Roll pastry to 1/8-inch thickness on surface. Cut into thirty 4-inch squares.
Spoon 1 tablespoon pineapple filling in center of each pastry square. Moisten edges of squares; fold pastry in half to form rectangles. Press edges firmly together to seal.
Place on ungreased baking sheets. Bake at 425° for 15 minutes or until lightly browned.